Paleoecology of Upper Harkless archaeocythan reefs in Esmeralda County, Nevada

Four previously unstudied reef localities occur in the upper Lower Cambrian (Bonnia-Olenellus Zone) in the Upper Harkless Formation in Esmeralda County, Nevada. These patch reefs were constructed on a shallow, carbonate platform in the subtidal zone by a consortium of archaeocyaths and calcimicrobes (Renalcis). A high diversity of dwelling organisms is found in varying quantities within and surrounding the reefs. Comparisons to the same age reefs in the Forteau Formation in Labrador, Canada preliminarily correlate these two localities. A comparison between modern sponges in Belize and archaeocyaths reveal similarities; Four phases of diagenesis occur showing synsedimentary, mixing zone, shallow and deep burial cementation. Stratigraphic analyses reveal a shallowing upward sequence from packstone, which encases the reefs, to calcareous sandstone. Data indicates that the shoreline prograded across the carbonate platform. This progradation is theorized to be a result of (1) climate change, (2) a prolonged standstill, or (3) sea level lowering.

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Geoscience

Grantor dc:publisher

University of Nevada, Las Vegas

Year

2001

Author dc:creator

• Hicks, Melissa K

Contributors dc:contributor

• Stephen M. Rowland

Statement dc:rights

• IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

Language dc:language

English

Identifier

https://oasis.library.unlv.edu/rtds/1322

OAI identifier oai:identifier

oai:oasis.library.unlv.edu:rtds-2321